Apparatus for swaging ferrules

ABSTRACT

Apparatus for swaging a ferrule or ferrules onto an outer wall of a cylindrical member includes a hydraulic power section and an adapter tool. The hydraulic section is disposed within a housing, and the adapter tool is at least partly retained in the housing and also is fully removable from the housing without affecting the hydraulic power section of the apparatus. The hydraulic section includes a piston that is moved under force of hydraulic pressure applied thereto from a hydraulic pressure source. The adapter tool includes a driven swaging die that is moved from a retracted position to an extended position in response to movement of the piston. The sleeve and anvil are releasably secured together so that the adapter tool can be removed from the housing as a unitary assembly. Size changes can be accommodated by removing a first adapter tool of a given size and replacing it with a second adapter tool of a different size. This changeover can be implemented without any disassembly or compromise of the hydraulic section. The apparatus also provide a visual indication that a swaging operation is completed by action of an indicator knob that axially pops out of the back end of the housing at the end of a swaging operation.

RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.09/667,662 filed on Sep. 22, 2000 now U.S. Pat. No. 6,463,778 forAPPARATUS FOR SWAGING FERRULES, which claims the benefit of U.S.provisional patent application Ser. No. 60/155,426 filed on Sep. 22,1999 for APPARATUS FOR SWAGING FERRULES the entire disclosures of whichare fully incorporated herein by reference.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to apparatus used to swage ferrules ontothe outer wall of cylindrical member such as a tube end. Moreparticularly, the invention relates to a swaging apparatus in which ahydraulic drive section is isolated and separable from a size adaptertool that includes a driven member that swages the ferrule by applyingan axial force thereto against a coupling nut. This application claimsthe benefit of U.S.

BACKGROUND OF THE INVENTION

Ferrule type tube fittings are well known and characteristically includea threaded coupling nut, a threaded coupling body and one or moreferrules that fit inside the coupling nut. The coupling body typicallyincludes a camming surface that engages a camming surface on a ferrule.A cylindrical member such as, for example, a tube end, is slid into thecoupling body with the ferrules closely surrounding the outer wall ofthe tube end. When the coupling nut is installed onto the threaded endof the coupling body, an axial force is applied to the ferrule orferrules which produces a swaging action thereby causing a radialdisplacement of portions of each ferrule body, causing the ferrules totightly grip the outer wall of the tube end.

In many applications the fitting can be assembled with the use of simplehand tools such as wrenches. However, with larger tube sizes and withtubing made of harder materials, it is often necessary to use fluidpressure to apply sufficient force to properly swage the ferrules ontothe tubing. Furthermore in some applications it is desirable to have theability to assemble many fittings in an expedient manner.

Many types of power assisted swaging apparatus have been developed overthe years. One type of such a tool is a hydraulic swaging apparatus inwhich a piston is driven axially by hydraulic pressure. The piston inturn displaces a driven member or anvil that applies the axial force tothe ferrules. Such apparatus are described in U.S. Pat. Nos. 3,722,064;3,810,296; 3,728,771; 4,873,755 and 5,027,489 the entire disclosures ofwhich are fully incorporated herein by reference.

A characteristic of known swaging apparatus is that often times thedriven member used to apply the axial force to the ferrules is integralwith the hydraulic piston. If the same size ferrule or tubing is alwaysgoing to be used, this is not an inconvenience, but as is morefrequently the case, the apparatus must be able to swage ferrules ofvarious sizes. Thus, a size change could require a disassembly of thehydraulic section as well. Alternatively, it is known to make the drivenmember separate from the piston, but even in such designs the drivenmember may be used to retain the piston in the apparatus housing, sothat if size changes need to be made, the hydraulic section is probablygoing to be disassembled or at a minimum prone to leakage.

It is therefore an objective of the present invention to provideapparatus for swaging ferrules onto cylindrical members using fluidpressure, with the apparatus having substantial flexibility in makingsize changes without compromising or needing to disassemble thehydraulic drive section of the apparatus. It is a further objective toprovide a more compact and user friendly swaging tool that is easier touse and provides a visual indication that a swaging operation has beensuccessfully completed.

SUMMARY OF THE INVENTION

To the accomplishment of the aforementioned and other objectives, and inaccordance with one embodiment of the invention, an apparatus forswaging a ferrule or ferrules onto an outer wall of a cylindrical memberincludes a hydraulic power section and an adapter tool. The hydraulicsection is disposed within a housing, and the adapter tool is at leastpartly retained in the housing and also is fully removable from thehousing without affecting the hydraulic power section of the apparatus.The hydraulic section includes a piston that is moved under force ofhydraulic pressure applied thereto from a hydraulic pressure sourceconnectable to the apparatus. The adapter tool includes a driven swagingmember or anvil that is moved from a first or retracted position to asecond or extended position in response to movement of the piston. Theadapter tool also includes a threaded sleeve onto which a coupling nutcan be installed. Preferably, but not necessarily, the sleeve and anvilare releasably secured together so that the adapter tool can be removedfrom the housing as a unitary assembly. Size changes can be accommodatedby removing a first adapter tool of a given size and replacing it with asecond adapter tool of a different size. This changeover can beimplemented without any disassembly or compromise of the hydraulicsection.

In accordance with another aspect of the invention, the apparatusincludes a visual indicator that a swaging operation has beensuccessfully completed. In the preferred embodiment, this visualindication is realized in the form of an indicator knob that pops outaxially from the back end of the apparatus when a swaging operation iscompleted. The knob is reset manually before the start of the nextswaging operation.

These and other aspects and advantages of the present invention will beapparent to anyone skilled in the art from the following description ofthe preferred embodiments in view of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may take physical form in certain parts and arrangementsof parts, preferred embodiments and a method of which will be describedin detail in this specification and illustrated in the accompanyingdrawings which form a part hereof, and wherein:

FIG. 1 is an apparatus for swaging ferrules in accordance with thepresent invention, illustrated in longitudinal cross-section in aninitial position before a swaging operation;

FIG. 2 is an exploded view of the apparatus in FIG. 1;

FIG. 3 is a schematic representation of the apparatus of FIG. 1assembled for use with a hydraulic source;

FIG. 4 is the apparatus of FIG. 1 illustrated in a second position atthe end of a swaging operation before reset;

FIG. 5 is an exploded view of the apparatus of FIG. 1 illustratinginstallation features of the adapter tool;

FIG. 6 is the apparatus of FIG. 1 illustrating a fluid couplinginstalled for a swaging operation; and

FIGS. 7A and 7B illustrate the use of a dead space between the swagingtool and the ferrule for fitting sizes other than the maximum swagestroke fitting.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to FIGS. 1 and 4, the invention will be described hereinin an exemplary manner for swaging two ferrules of a conventional tubefitting onto a tube end, however, this is for purposes of illustrationand explanation and should not be construed in a limiting sense. Thoseskilled in the art will readily appreciate that the invention describedherein can be used to swage single ferrules onto tube ends, and furthercan be used to swage ferrules onto cylindrical members other than justtube ends, among them being cylindrical members such as tubingextensions on flow control devices to name one example. Additionally,various aspects of the invention are described herein, with theexemplary embodiment illustrating the use of various aspects of theinvention together. Those skilled in the art, however, will readilyappreciate that the individual aspects of the invention may be usedindividually or in any variety of combinations based on the operationalrequirements for a particular swaging operation or tool.

In accordance with the invention, the swaging apparatus is generallydesignated with the numeral 10. The swaging apparatus 10 issubstantially self-contained within a housing 12, but for a connectablesource of pressurized hydraulic fluid that is further describedhereinafter. Other fluids could be used, including water with ahydrostatic pump, or gas pressure, for example.

The housing 12 can functionally be viewed as comprising two basicsections, a hydraulic power section 14 and a swaging section 16. Thehydraulic section 14 includes a drive piston 18, a hydraulic connectorassembly 20 and a swaging completion indicator assembly 22. An actuatorshaft 24 extends through the housing 12 and lies along a centrallongitudinal axis X of the apparatus 10. The piston 18 is a generallycylindrical member that is centrally disposed within a piston bore 30and in its retracted or returned position (as illustrated in FIG. 1)bottoms against a counterbore 32 of the housing 12. The piston 18includes a central shaft bore 34 through which the actuator shaft 24extends. A conventional piston seal ring 36 is provided in a seal recess37 to seal the piston 18 against the housing bore 30 to preventhydraulic fluid loss. In this example, the seal 36 includes anelastomeric o-ring 36 a and a Teflon™ backing ring 36 b which functionsto prevent extrusion of the seal 36 a under pressure. Different sealarrangements can be used as required. Similar seal arrangements areprovided on the shaft 24 as indicated in the drawings.

The piston 18 is appropriately dimensioned and machined to allow for lowfriction translation along the central axis X. The piston 18 furtherincludes a hydraulic fluid recess 38 that extends radially from theshaft bore 34 and is in fluid communication with a transverse bore 40 inthe actuator shaft 24. The recess 38 forms a small fluid cavity thathydraulic fluid enters to apply pressure to the back side 18 a of thepiston 18. When hydraulic fluid under pressure is supplied to the cavity38 and back side 18 a the piston 18 is forced or moved forward or to theleft as viewed in FIG. 1.

A central longitudinal bore 42 extends from the back or inlet end of theactuator shaft 24 a just beyond the location of the transverse bore 40.The longitudinal bore 42 opens into the recess 38. By this arrangement,hydraulic fluid is supplied to drive the piston 18.

The actuator shaft 24 includes a circumferential recess 44 that receivesand retains a removable snap ring 46. When the snap ring 46 is installedwith the piston 18 positioned on the actuator shaft 24, the piston 18 isaxially captured between the snap ring 46 and the housing wall 32. Whenthe piston 18 is forced axially forward it pushes on the snap ring 46thus also driving the shaft 24 forward therewith. The snap ring 46 alsocauses the piston 24 to be returned to the reset position illustrated inFIG. 1 when hydraulic pressure is removed from the piston 24 (the shaft24 is biased rearward as viewed in FIG. 1 by a shaft spring 160 furtherdescribed herein). A second piston seal arrangement 48 is provided in aseal groove 50 formed in the actuator shaft 24 at a location that isaxially forward of the piston recess 38 to seal against fluid loss alongthe inner piston shaft bore 34.

The piston 18 includes a reduced diameter piston drive face 52. Thereduced diameter of the drive face 52 as compared to the diameter of thepiston 18 at the back end thereof forms a circumferential space 54 thatis bounded by a piston stop surface 56. A second and removable snap ring58 is positioned in a groove 60 formed in the housing 12 just axiallyforward of the piston 18 when the piston is in the retracted positionillustrated in FIG. 1. The snap ring 58 limits the maximum axial strokeof the piston 18 by interfering with the stop surface 56 when the pistonhas moved forward a distance that is defined by the axial gap betweenthe stop surface 56 and the back surface of the snap ring 58.

The piston 18 drive face 52 drivingly contacts or engages a swaging dieor anvil 70 at a back side 70 a thereof. The swaging die 70 is agenerally cylindrical structure with a tapered forward mouth 72. Thistapered mouth 72 engages a front ferrule F1 and applies a camming actionto swage the ferrule onto a tube end, as will be further describedhereinafter. The swaging die 70 includes an inner bore 74 that closelyreceives a tube end (not shown in FIG. 1). The tube end is inserteduntil it bottoms on a counterbore 76. The counterbore 76 is providedwith a raised ridge or bead 78 that is shown in an exaggerated size inFIG. 1. This bead 78 forms a small indentation in the tube end after aproper swaging operation, thus providing a positive and visually simpleverification that the tube end was fully inserted into the die 70 priorto the swaging operation.

The swaging die 70 includes a central shaft bore 80. A forward end 24 bof the actuator shaft 24 extends forward into the die bore 80. A baffleplug 84 is installed into the bore 80. The plug 84 includes a throughhole 86 that allows hydraulic fluid to drip out of the die 70 when therelief valve 120 is open.

The swaging die 70 is slideably retained within a generally cylindricaladapter sleeve 90. The adapter sleeve 90 is partly retained within thehousing 12, and a forward portion 90 a thereof extends axially beyondthe forward end 12 a of the housing. The adapter sleeve 90 isdimensioned to be installed into the housing 12 by a slip fit. The slipfit installation makes installation easier and the adapter 90 is lessprone to damage such as damage to threads. The forward end of theadapter sleeve 90 a includes an externally threaded portion 92 ontowhich an internally threaded coupling nut (not shown in FIG. 1) can beinstalled. The diameter of the end portion 90 a is smaller than thediameter of the main sleeve body portion 90 b, thereby forming a forwardretainer face 94. A retainer in the form of a third removable snap ring96 is fitted into a groove 98 formed in the forward portion of thehousing 12. The snap ring 98 is used to securely retain the adaptersleeve 90 axially in position within the housing 12.

The adapter sleeve 90 includes a counterbore 100 that is of a largerdiameter than the outer diameter of the swaging die 70. The swaging 70die and the adapter sleeve 90 thus form an annulus 102. A spring 104 isdisposed in the annulus 102 and is held in compression between thecounterbore 100 and an outward extending flange 106 formed near the backend 70 a of the swaging die 70. The spring 104 axially biases theswaging die 70 and the adapter sleeve 90 apart. The adapter sleeve 90includes a snap ring groove 108 formed near the back end of the sleeve90. A retainer in the form of a fourth removable snap ring 110 engagesthe back face of the die flange 106 to hold the adapter sleeve 90 andthe swaging die 70 together as a single unitary adapter tool assembly112. Other mechanisms for holding the sleeve 90 and die 70 together asan assembly 112 may be used, as will be readily apparent to thoseskilled in the art. For example, a threaded collar may be used in placeof the fourth snap ring 110, or the die 70 may be coined with the sleeve90.

When assembled as in FIG. 1, the spring 104 is not fully compressed,thereby permitting a limited but predetermined amount of relative axialmovement between the die 70 and the sleeve 90. This permits the adaptertool assembly 112 to be installed into the housing 12 after the piston18 is installed, with positive engagement between the piston 18 and thedie 70. After the assembly 112 is installed, there is still sufficientspace for the spring 104 to be compressed. In this manner, axialdisplacement of the piston 18 in the forward direction causes acorresponding forward displacement of the die 70. Tolerances arecontrolled so that the piston 18 hits the snap ring 58 before the spring104 becomes fully compressed into a cylindrical incompressible form.This allows the maximum swaging stroke to be tightly controlled bycontrolling the axial gap between the piston face 56 and the snap ring60, rather than having to control the dimensions of the spring 104. Notethat, in the absence of hydraulic pressure in the passage 42, the spring104 biases the die 90 and the piston 18 rearward towards the retractedor pre-swage position illustrated in FIG. 1. However, the fourth snapring 110 limits the extent to which the spring 104 pushes the piston 18to the wall 32; rather another bias spring is used for that purpose aswill be apparent hereinafter.

In accordance with one feature of the invention, the adapter assembly112 is purposefully designed to be removable from the housing 12 withoutcompromising the integrity of the hydraulic section 14. The dimensionsof the adapter sleeve 90 and the swaging die 70 are directly related tothe size of the ferrules being swaged, the tube diameter, and the sizeof the associated coupling nut. Thus, in order to swage different sizeferrules and tubing, the swaging die 70 and the adapter sleeve 90 mustbe easily interchangeable. Different sized couplings can be accommodatedwith the apparatus 10 simply by using a different adapter assembly 112.The slip fit installation of the adapter assembly 112 simplifies andspeeds up change over without compromising the hydraulic section 14.

Because of the threaded engagement between the coupling nut and theadapter sleeve 90, the sleeve 90 may tend to rotate when a coupling nutC is installed onto the adapter sleeve 90. This rotation may beundesirable in some applications, and therefore an anti-rotation pin 114may be installed in a transverse hole 116 through the housing 12. Thehole 116 is positioned adjacent an axial slot 118 formed in the outerperiphery of the adapter sleeve 90 at the back end thereof. Byinstalling the pin 114 first before the assembly 112 is installed, theassembly 112 can be easily oriented during installation to align theslot 118 with the protruding end of the anti-rotation pin 114.

The shaft 24 may be provided with a relief valve assembly 120. Therelief valve assembly 120 is used to prevent over pressurizing thehydraulic section 14 of the apparatus 10. This may be particularlyimportant when a manually operated hydraulic pump is used to provide thehydraulic pressure for operating the apparatus 10. In a portion of theshaft 24 downstream from the transverse bore 40, a counterbore 122 isformed, and a valve orifice 124 extends therethrough. A poppet-stylerelief valve stem 126 is centrally disposed in a valve chamber 128formed in the actuator shaft 24. A valve bias spring 130 is disposed inthe valve chamber 128 and biases the valve poppet 126 closed asillustrated in FIG. 1. A valve set screw 132 is threadably inserted intothe threaded bore 82 of the actuator shaft 24. Adjusting the axialposition of the screw 132 in the bore 82 sets the pressure at which therelief valve will crack open to relieve excess hydraulic pressure. Theset screw 132 and the baffle plug 84 include through bores 136, 86respectively through which hydraulic fluid is released to reduce excesspressure in the hydraulic section 14. The reduced orifice 124 prevents ahigh flow of hydraulic fluid when the valve 120 opens. The presence offluid in the swaging die 70 can be readily detected and the pressurerelieved at the source. Once the pressure drops, the valve 120 closes,thereby preventing the loss of an excess amount of hydraulic fluid.

In accordance with another aspect of the invention, the indicatorassembly 22 is used to provide immediate visual and audible feedback tothe operator that a swaging operation has been completed. This helps theoperator from over pressurizing the hydraulics or over swaging the fluidcoupling. In this exemplary embodiment, the indicator 22 is realized inthe form of an indicator knob 140 that axially pops out of the back endof the housing 12 at the end of a swaging operation.

The indicator knob 140 is a generally cylindrical element that includesa central body portion 142, a forward end 144 and a back end 146. Theforward end 144 includes a central axial bore 148 having an inwardshoulder 150 at the back end thereof.

A spring alignment washer 152 is provided around the actuator shaft 24against a counterbore 154 in the housing 12. A knob spring 156 isdisposed between the washer 152 and the shoulder 150 in the knob bore148. This spring biases the knob 140 rearward as viewed in FIG. 1, or inother words to a position that indicates completion of a swagingoperation. In FIG. 1 the knob 140 is in the pre-swage position, and inFIG. 4 the knob 140 is illustrated in the popped-out position after aswaging operation is completed.

The actuator shaft 24 further includes an outward extending shoulder158. A shaft spring 160 is positioned in the knob bore 148 between thewasher 152 and the shaft shoulder 158. The shaft spring 160 biases theshaft 24 away from the tool end of the assembly 10, or in other wordsthe spring 160 biases the shaft 24 so as to return the piston 18 to theinitial or retracted position illustrated in FIG. 1.

The shaft 24 is further provided with a ball detent 162 in the form of atapered shoulder that extends radially outward from the shaft 24 body.The indicator knob 140 includes a transverse threaded bore 164 withinthe knob central body 142. The bore 164 is positioned such that when theknob 140 is in the reset position of FIG. 1, the bore 164 is radiallyaligned with the ball detent 162. A detent ball 166 is positioned in thebore 164 and a detent spring 168 is captured within the bore 164 betweenthe ball 166 and a threaded detent retainer screw 170. Note that inpractice there are actually three (or more) detent balls used that areevenly spaced around the circumference of the indicator knob 140 (onlyone ball 166 is shown in the drawings). The use of the three balls keepsthe indicator knob 140 centered. Adjustment of the position of thedetent retainer screw 170 in the bore 164 is used to adjust the force ofthe detent ball 166 against the detent shoulder 162. This force must besufficient to prevent the ball 166 from being displaced against thespring 168 due to the rearward bias applied to the knob 140 by the knobspring 156. Alternatively, the detent ball 166, spring 168 and screw 170may be a single subassembly within a threaded housing (not shown) thatis installed into the bore 164. The indicator knob 140 may be knurled asat 140 a to assist in gripping the knob 140 to reset its position. Theshaft 24 includes a flange 186 that keeps the knob 140 on the shaftafter it pops out. The knob 140 is dimensioned so that in its resetposition illustrated in FIG. 1 the central body portion 142 is hiddenfrom view by the rear portion 12 b of the housing 12. An anti-tampersleeve 169 may be slipped over the knob 140 to cover the detentmechanism. This sleeve may be colored so as to provide indication thatthe indicator knob 140 has tripped.

The back end of the shaft 24 includes the hydraulic connector assembly20. In this embodiment, the connector 20 is an internally threaded endof the actuator shaft 24. A threaded end connector of a hydraulic hoseis installed into this bore. In the illustrated embodiment (see FIG. 3),a swivel fitting 172 is installed on the outlet of the hydraulic pump190. The fitting 172 may be conventional in design and retains ahydraulic hose coupling 182 at the end of a hydraulic hose end from thehydraulic source 190. The swivel fitting 172 simplifies connection ofthe hydraulic hose to the apparatus 10 by adjusting for twist ormisalignment of the hydraulic hose relative to the apparatus 10.

In FIG. 3 the apparatus 10 is illustrated connected to a hydraulic pump190 via a hydraulic hose 192. In this example, the pump 190 may be anyconventional hand operated hydraulic pump, such as model no. P-12available from Power Team, Owatonna, Wis.

With reference to FIGS. 1, 4 and 6, operation of the exemplary swagingapparatus 10 begins with the apparatus 10 in the condition illustratedin FIG. 1. If a swaging operation had been previously completed, theindicator knob 140 is manually pushed axially inward into the housing 12by gripping the knob end 146 and pushing the knob 140 forward until theball 166 engages the detent 162.

The hydraulic source is connected to the actuator shaft 24. A tube end Tis inserted into the adapter assembly 112 until it bottoms against thedie wall 76. In this example, a two-ferrule fitting is illustrated. Nexta front ferrule F1 is slipped onto the tube end followed by a rearferrule F2. A coupling nut C is then installed on the adapter sleeve 90and tightened down to a hand tight position. In the hand tight positionillustrated in FIG. 6, the coupling nut C forward end aligns with thelast or inner most thread 92 a on the adapter sleeve 90. This alignmentin the hand tight position provides an indication that the ferrules F1and F2 are installed properly and that the piston 18 is in the fullyretracted initial position prior to a swaging operation.

The hydraulic pump 190 is then actuated. Hydraulic pressure buildsbehind the piston 18 and eventually moves the piston forward (leftwardas viewed in FIGS. 1 and 4). As the piston advances, it pushes theswaging die forward against the bias of the spring 104 and the spring160. The piston 18 also pushes against the piston retainer snap ring 46,thus also causing the shaft 24 to advance forward with the piston 24. Asthe die 70 advances, it swages the ferrules F1 and F2 onto the tube endT by a camming action of the tapered mouth 72 against the tapered noseof the front ferrule.

A proper swage is predetermined by the axial travel distance “Y” of thedie 70 (FIG. 4). This distance is typically based on empirical data anddesign criteria and will vary based on the size of the fitting. Thisdistance control is conveniently built into the adapter assembly byappropriate dimensioning of the swaging die 70 and the adapter 90 forthe particular fitting to be used therewith. Thus for various fittingsizes there typically will be an associated number of adapter assemblies112. For example, the tool 10 is typically designed to swage a varietyof fitting sizes, wherein one of those fittings will require the maximumstroke. The swaging die 70 is appropriately sized to move this maximumdistance Y in response to displacement of the piston 18 to produce aproper swaging action on the fitting having the highest strokerequirement. Note that the fitting having the largest stroke requirementneed not necessarily be the largest sized fitting. For other fittingsizes that will be used with the tool 18 and require less stroke, theassociated adapter assembly 112, and particularly the swaging die 70,are sized to include an appropriate dead space before the tapered mouth72 contacts the front ferrule F1. This dead travel space can beconveniently built into the adapter assembly 112 (for example bycontrolling the length of the die 70) because the die 70 is pushedbackwards relative to the adapter sleeve 90 by the return spring 104when the hydraulic pressure is removed.

The stroke Y of the swaging die 70 is controlled by appropriatedimensioning of the washer 152. As the shaft 24 advances with the piston18, the indicator knob 140 also advances forward until the knob contactsthe top surface 152 a of the washer 152. After this contact is made,further movement of the shaft 24 causes the indicator knob to beactuated. Thus, appropriate selection of the washer 152 dimensions willset the stroke of the die 70. This distance that the die 70 travels willbe equal to the stroke Z of the piston plus the distance that the shaft24 travels after the knob 140 hits the washer 152 until the balls 166clear the detent 162, at which point the indicator knob pops out toindicate completion of the swaging operation. Over swaging is preventedby the piston 18 hitting the stop ring 58. If hydraulic pressurecontinues to build after the piston is stopped, the relief valve 120will open and release the hydraulic pressure.

FIGS. 7A and 7B illustrate this dead space concept. In FIG. 7A there isillustrated a typical front ferrule F3 and rear ferrule F4 installed ona tube end (not shown) and inserted in the swaging tool 10 with the toolin the pre-swage condition. The coupling nut C is also shown installedon the threaded end 92 of the adapter sleeve 90. In this example, theferrule F3 is that ferrule that requires the maximum piston 18 stroke,and hence the maximum swaging die 70 stroke, to swage the ferrules ontothe tube end. Accordingly, the length of the adapter sleeve 90 isselected such that the forward end 90 a of the sleeve 90 does not abutthe ferrule F3 flange face FF before the die 70 engages the forward endFG of the ferrule F3. Therefore, all of the axial displacement of thedie 70 is used for the swaging operation.

In FIG. 7B, a ferrule F5 is to be swaged that requires a shorter strokeof the die 70. Again, as in FIG. 7A, the components are shown in theassembled pre-swage position (corresponding to the set-up of FIG. 1).Since the piston 18 and the die 70 will always be displaced the sameaxial distance, some of that stroke will not be used for swaging theferrule F4. As illustrated, the shorter ferrule F4 (as compared to theferrule F3 that requires the maximum stroke) thus has its flange FH abutthe free end 90 a of the die 70 before the forward end FI of the ferruleengages the die 70, thus producing an axial gap or “dead space” Gbetween the ferrule F5 and the die 70. As the piston 18 and the die 70initially advance axially, this gap will first be taken up without anyswaging action on the ferrule F5. The size of the gap G can be selectedby appropriate dimensioning of the die 70 (keeping in mind that when theferrule or fitting size changes, the adapter tool 112 which includes thesleeve 90 and the die 70 is also changed) so that only that portion ofthe total die displacement Y needed for a proper swage is actually used.By having the shorter stroke ferrules F5 engage the adapter sleeve 90 atthe ferrule flange FH, a swaging operation always has a common startingpoint of the ferrule relative to the die 70. Therefore, the actual swagestroke can be precisely set by appropriate dimensioning of the die 70.This dead space feature will typically be used when the various sizes offerrules to be swaged require different swage strokes, which correspondsto different thread pitch on the fitting.

Use of the washer 152 permits a convenient method for calibrating theapparatus 10. In any swaging tool, the stroke that the swaging dieadvances is important to assure that a proper swage was effected.However, there are tolerance stack-ups with the ferrules themselves andtolerance stack-ups in the adapter tool assembly 112. Therefore, it isdesirable if the stroke of the piston 18 can be precisely controlledwith zero error. In accordance with this aspect of the invention, thetool 10 is first assembled using a washer 152 of nominal axialdimension. The actual dimension is not critical. Next, a ferrule andtube end are installed in the same manner as if a swaging operationwould be performed. Next, the indicator knob is reset to the pre-swageposition illustrated in FIG. 1. Next, the operator relatively slowlyadvances the shaft 20 (which corresponds directly with advancement ofthe piston 18) until the indicator knob 140 is released. The axialdisplacement of the shaft/piston to the point of knob actuation ismeasured. If the measured displacement is not the desired displacementto effect a proper swage, the nominal washer 152 is replaced with adifferent washer 152 having an axial dimension selected such that thepiston stroke will be precise, thus reducing to zero any error thatcould contribute to an incomplete or over swage. The distance of thepiston stroke is selected to simulate or replicate the axialdisplacement of the coupling nut in a typical fitting during a pull-upoperation of the fitting.

As the shaft 24 advances with the piston 18, the knob hits the washer152 and thereafter further movement of the shaft 24 causes the detentballs 166 to ride up over the detent 162 by being displaced into thebore 164 against the force of the bias spring 168. When the detent 162passes the ball 166, the indicator sleeve 140 is free to axially snap orpop rearward under the bias force of the indicator spring 156. The knob140 hits the flange 186 and makes an audible click. Additionally, theouter surface 142 a of the knob may be treated as with color or otherfinish to easily make a visual determination that the sleeve 140 is inthe extended or post-swage position.

When the indicator knob 140 pops out, the operator knows immediatelythat the swaging operation is completed and can then relieve thehydraulic pressure. Once the pressure drops below a value that offsetsthe force of the shaft spring 160, the spring 160 returns the shaft 24along with the piston 18 and the swaging die 70 to the position shown inFIG. 1. The operator manually resets the knob 140 as previouslydescribed hereinabove.

FIG. 5 illustrates the main subassemblies of the apparatus 10. Inaccordance with another feature of the invention, a typical fittingassembly includes the coupling nut C and a front and rear ferrule F1,F2. By removing the adapter sleeve snap ring 96, the swaging section 16in the form of the adapter assembly 112 can be removed as a singleassembly to simplify size changeover. The hydraulic section 14 and theindicator assembly 22 remain installed in the housing 12 and no sealsare disturbed or compromised as a result of removing the swaging section16.

Additional visual indications are provided with the position of theindicator knob and the shaft. As illustrated in FIG. 1, the central body142 of the indicator knob 140 is flush with the rear face of the housing12, as at 194. Also, the shaft flange 186 is flush with the indicatorknob, as at 196. In the initial pre-swage position of FIG. 1, theseflush alignments indicate to the operator that the piston 18 and theshaft 24 are fully returned to the initial start position, the indicatorknob has been reset, the tool 10 is not damaged and the hydraulicpressure in the tool has been released.

Obviously, modifications and alterations will occur to others upon areading and understanding of this specification. It is intended toinclude all such modifications and alterations insofar as they comewithin the scope of the appended claims or the equivalents thereof.

What is claimed is:
 1. Apparatus for installing a ferrule type fittingonto an outer wall of a cylindrical member by swaging the ferrule ontothe cylindrical member, the fitting including a threaded coupling nut,the apparatus comprising: a housing; a piston in said housing with saidpiston being movable between a first position and a second position inresponse to fluid pressure when applied to said piston; and an adaptertool partially retained in said housing; said adapter tool comprising asleeve that is threaded at one end to receive the coupling nut and ananvil; said anvil being moveable relative to said sleeve between a firstanvil position and a second anvil position to swage a ferrule onto thecylindrical member; said anvil and sleeve having a slip fit installationinto said housing and being retained in said housing by other than athreaded engagement.
 2. The apparatus of claim 1 wherein said anvil isbiased relative to said sleeve toward said anvil position thatcorresponds to an initial pre-swage position.
 3. The apparatus of claim2 comprising a spring captured between said sleeve and said anvil tobias said anvil towards said pre-swage position.
 4. The apparatus ofclaim 1 wherein said piston moves a defined distance between its firstand second positions during a swaging operation, said defined distancebeing less than a defined maximum stroke of said anvil relative to saidsleeve; said defined distance being controlled in part by a positivestop to limit axial movement of said piston thereby preventing overswaging.
 5. The apparatus of claim 1 wherein said piston and said anviltranslate along a common axis; and an indicator that provides a visualindication to an operator that a swaging operation is completed; saidindicator comprising a member that is displaced along said axis.
 6. Theapparatus of claim 5 wherein said indicator comprises a knob that isaxially displaced between a first and a second position.
 7. Theapparatus of claim 6 wherein said knob is releasably retained in saidfirst position by a detent device.
 8. The apparatus of claim 6 whereinsaid knob moves relative to an actuator shaft that is coupled to saidpiston; said knob being biased to second position.
 9. The apparatus ofclaim 8 wherein said knob moves to said knob second position after apredetermined relative axial movement between said knob and said shaft.10. The apparatus of claim 9 wherein hydraulically pressure is appliedto said piston by manual control of a fluid source by an operator; saidknob moving to said knob second position to indicate to an operator torelease hydraulic pressure.
 11. The apparatus of claim 1 comprising anactuator shaft coupled to said piston; said shaft having a central boretherein that provides a fluid conduit for pressurized fluid to drivesaid piston.
 12. The apparatus of claim 11 comprising a relief valvedisposed within said shaft.
 13. The apparatus of claim 1 wherein saidanvil and sleeve are dimensioned independent of said housing and saidpiston so that different size anvil and sleeve combinations may beinstalled in said housing to accommodate swaging different sizedfittings without changing said housing or piston.
 14. The apparatus ofclaim 1 wherein said piston comprises a reduced diameter drive face thatcontacts a back side of said anvil; said piston reduced diameter driveface being sufficiently less than said sleeve inner diameter to form acircumferential space between said piston and said sleeve wherebysleeves having different sized inner diameters are used to swagecorrespondingly different sized ferrules.